The CF was painted using an old nylon stocking. (a new one would probably have been better) The part was first painted with Tamiya's X-18 semi gloss black. Then XF-56 metallic grey through the stocking. Make sure you use little pressure on the airbrush and spray a few mist coats without moving the stocking. After this had dried I applied X-19 smoke untill the color matched the color on my reference pics.
Offcourse you can't get a super-clean pattern as with the decals, but the result is good if you want a CF-effect.
This is a picture I took before the smoke coat, after the metallic grey coat:
